Re: RA/XCR Development & Background Info?
No problem - I don't see your posts as a hijack! I just like learning more about XCR! Some interesting points were made. Thanks for the info! Keep it coming!
I think that if you are looking for R&D info regarding the XCR, Alex and his crew would be the best starting point, as they know where the bodies are buried, so to speak.
Best as I know (which might not be very much), the XCR started when the SPR-V was cancelled (due mostly, IMO, to the fact that RA's model, the RAV02, was better than KAC's SR-47).
SOCOM then brought the SPR-V and SCAR programs together, killed the SPR-V, then added a requirement for round interchangeability in the SCAR program.
On 23 March, 2004 SOCOM changed the requirements for EGLM so that is was to be compatible with the SCAR-L, SCAR-H, as well as be a stand alone weapon.
On 25 March, 2004 SOCOM changed the requirements for SCAR to include the requirement for EGLM compatibility.
This gave the SCAR participants two months to 'make it happen'.
Now, the leader for the EGLM contract was FNH, of Columbia SC.
FNH, of Columbia SC was also submitting a carbine for the SCAR competition.
Now, two months out, the program in which FNH had the inside track on was merged into a program in which FNH was submitting examples.
FNH said that they had to do no redesign of their SCAR examples because they were designed to be compatible with the EGLM from the outset.
???
I'm not sayin', just sayin' Ya know what I mean.
Another example of this is in the so-called Crane 'O' ring.
M-4's were having issues with extraction. After much review and analysis, they determined that the std. extractor and extractor insert (blue) were not providing enough tension, causing the extractor to slip.
A new, stronger, extractor spring and stiffer insert (black) was installed. Colt also developed an even stronger spring and insert (gold) to no effect. The PM (US Army Infantry) said that the 5-coil spring and black insert was "good enough".
NSW was still having extraction issues with their M-4 and they reached out to other's in the industry for assistance (because by now SOCOM felt that Colt was not 'respecting' them, vis-a-vie their issues with the M-4).
One of the companies that came to IN, was MGI. In due course, Mack designed a elastomer insert that provided constant pressure so that the extractor would not lose tension and continue to grip the case rim. He designed this to provide at least 30,000 to 50,000 compressions w/o losing its shape and used a material that was heat resistant to at least 700 degrees.
What did Crane do?
After seeing this, and the price tag for each insert (because MGI had to recoup R&D costs as well as make some coin on the deal), they went out and specified Viton ETP O-rings (size 006) that are only rated to 400 degrees and last around 10,000 compressions because the minimum bolt life for the M-4 is 5,000 rounds.
Oh, did I mention that you can pick these up at any well stocked auto repair store for $3.23 per 5 pack at McMaster-Carr?
Where does MGI go to recoup their monies?
Now, the Viton ETP O-ring does
most everything the MGI's D-Fender product does, and at 1/20 the price.
That said because the O-ring came from Crane and NSW, it is "the" thing and therefore MGI is just being a crybaby and "overcharging" the consumer.
You want something that does
most things the D-Fender will for $0.65 each? Then get the O-ring.
You want something that will last longer than your barrel, but costs ~$12.00. Get the D-Fender.
